N-Acyl-piperidone compounds

ABSTRACT

N-Acyl-piperidones of the formula ##STR1## wherein R represents methyl or chloro, and their use as antidotes for protecting crop plants from herbicidal damage.

This invention relates to certain new N-acyl-piperidone compounds and totheir use as antidotes for protecting crop plants from herbicidaldamage, especially by herbicidally active thiolcarbamates andacetanilides. The invention further relates to new active compoundcombinations of the N-acyl-piperidone compounds and certain herbicidallyactive carbamates and acetanilides which have particularly goodselective herbicidal properties.

"Antidotes" ("safeners") in the present connection are to be understoodas substances which are capable of specifically antagonising the harmfuleffects of herbicides on crop plants, that is to say of protecting thecrop plants, without thereby noticeably influencing the herbicidalaction on the weeds to be combated.

It is known that, when used for combating weeds in maize and othercrops, certain thiolcarbamates and acetanilides cause damage to the cropplants to a greater or lesser extent. It is furthermore known that suchcompounds as, for example, N-dichloroacetyl-2-ethylpiperidine andN-dichloroacetyl-cis/transdecahydroquinoline are suitable for reducingdamage to crop plants by thiolcarbamates or acetanilides (see DE-OS(German Published Specification) No. 2,218,097). However, the activityof these substances as antidotes is not always completely satisfactory.

The present invention now provides, as new compounds, theN-acyl-piperidones of the general formula ##STR2## in which R representsmethyl or chloro. The invention also provides a process for thepreparation of a N-acyl-piperidone of the formula (I) in whichpiperidone-(4) of the formula ##STR3## or its hydrochloride is reactedwith alkanoyl chlorides of the formula ##STR4## in which R has themeaning indicated above, if appropriate in the presence of a diluent andif appropriate in the presence of an acid-binding agent.

It has been found that N-acyl-piperidones of the formula (I) areoutstandingly suitable for protecting crop plants from damage byherbicidally active thiolcarbamates or by herbicidally activeacetanilides.

It has also been found that the new active compound combinationscomprising an N-acyl-piperidone of the formula (I) and at least oneherbicidally active thiolcarbamate and/or at least one herbicidallyactive acetanilide are outstandingly suitable for selectively combatingweeds in crops of useful plants.

Surprisingly, herbicidal damage to crop plants by thiolcarbamates or byacetanilides is better suppressed when N-acyl-piperidones of the formula(I) are also used than when the known compoundsN-dichloroacetyl-2-ethyl-piperidine andN-dichloroacetyl-cis/trans-decahydroquinoline, which are chemicallysimilar substances of the same type of action, are employed. Moreover,it was not to be expected that the active compound combinationsaccording to the invention have better selective herbicidal propertiesthan active compound combinations which consist of at least oneherbicidally active thiolcarbamate or at least one herbicidally activeacetanilide and N-dichloroacetyl-2-ethyl-piperidine, which is known asan antidote, or N-dichloroacetyl-cis/trans-decahydroquinoline, which islikewise known as an antidote.

If piperidone-(4)-hydrochloride hydrate and dichloroacetylchloride areused as starting substances, the course of the process according to theinvention can be represented by the following equation: ##STR5## Thepiperidone-(4) of the formula (II), which is required as startingsubstance in the process according to the invention, is already known(compare Koenigs, Neumann; Ber.dtsch.chem. Ges. 48 (1915)960). Thealkanoyl chlorides of the formula (III), which are required as reactioncomponents in the process according to the invention, are known as well(compare DE-OS (German Published Specification) No. 2,218,097).

The process for the preparation of the N-acyl-piperidones of the formula(I) is preferably carried out in the presence of a diluent. Diluentswhich can be used in this process are water and inert organic solvents.These solvents include, as preferences, ketones, such as diethyl ketoneand methyl isobutyl ketone; nitriles, such as propionitrile andacetonitrile; ethers, such as tetrahydrofuran or dioxan; aliphatic andaromatic hydrocarbons, such as petroleum ether, benzene, toluene andxylene; halogenated hydrocarbons, such as methylene chloride, carbontetrachloride, chloroform or chlorobenzene; esters, such as ethylacetate; and formamides, such as, in particular, dimethylformamide.

Possible acid-binding agents for carrying out the abovementioned processare any customary acid acceptors.

These include, as preferences, alkali metal hydroxides, such as sodiumhydroxide and potassium hydroxide, alkali metal carbonates, such assodium carbonate, potassium carbonate and sodium bicarbonate, and lowertertiary amines, such as triethylamine, dimethylbenzylamine, pyridine,diazabicyclooctane and 1,8-diaza-bicyclo[5.4.0]undec-7-ene. However,piperidone of the formula (II) employed in excess can alsosimultaneously function as the acid-binding agent. In this case, it isnot necessary to add an additional acid-binding agent.

The reaction temperatures can be varied within a substantial range inthe above-mentioned process. In general, the reaction is carried outbetween 0° and 100° C., preferably between 10° and 80° C.

In carrying out the above-mentioned process, 1 to 2 mols of alkanoylchloride of the formula (III) and, if appropriate, 1 to 2 mols ofacid-binding agent are preferably employed per 1 mol of piperidone-(4)of the formula (II). The isolation of the reaction products is effectedby customary methods. In general, a procedure is followed in which, whenthe reaction has ended, water is added to the reaction mixture, theorganic phase is separated, the aqueous phase is extracted several timeswith an organic solvent, the combined organic phases are dried andconcentrated.

As already mentioned, the N-acyl-piperidones of the formula (I) aresuitable for protecting crop plants from damage by herbicidally activethiolcarbamates and acetanilides without noticeably influencing theirherbicidal action.

The N-acyl-piperidones of the formula (I) can preferably be used asantidotes for protecting crop plants from damage by herbicidally activethiolcarbamates of the general formula ##STR6## in which R¹ representslower alkyl, benzyl, chlorobenzyl or alkoxybenzyl and

R² and R³ independently of one another represent alkyl with 2 to 4carbon atoms or cyclohexyl, or R² and R³, together with the adjacentnitrogen atom, represent a five-membered to seven-membered heterocyclicring,

and for protecting crop plants from damage by herbicidally activeacetanilides of the general formula ##STR7## in which R⁴ represents anoptionally substituted N-containing heterocyclic radical,

X and Y are identical or different and represent alkyl,

Z represents halogen and

n represents 0, 1 or 2,

and herbicidally active acid-addition salts and metal salt complexesthereof, and of the general formula ##STR8## in which A representsoxygen, sulphur or the grouping >NR¹⁰,

R⁷ represents hydrogen or alkyl,

R⁸ represents hydrogen, alkyl, haloalkyl, alkenyl, alkynyl, cycloalkyl,halogen, optionally substituted aryl, optionally substituted aralkyl orthe grouping --OR¹¹, --SR¹¹ or NR¹⁰ R¹¹,

R¹⁰ represents hydrogen, alkyl or optionally substituted aryl,

R¹¹ represents hydrogen, alkyl, haloalkyl, alkenyl, alkynyl, cycloalkylor optionally substituted aralkyl,

R⁵ represents alkyl,

R⁶ represents alkyl or halogen,

R⁹ represents halogen and

p represents 0, 1 or 2,

and of the formula ##STR9## and of the formula ##STR10##

Specific examples of thiolcarbamates of the formula IV which may bementioned are: S-ethyl N,N-dipropyl-thiocarbamate, S-ethylN,N-diisobutylthiocarbamate, S-propyl N-butyl-N-ethylthiocarbamate,S-propyl N,N-diisopropylthiocarbamate, S-ethyl N,N-diethylthiocarbamate,S-ethyl N-ethyl-N-cyclohexylthiocarbamate, S-ethylhexadro-azepine-1-thiocarbamate, S-p-methoxybenzylN,N-diethylthiocarbamate, S-p-chlorobenzyl N,N-diethylthiocarbamate,S-benzyl N,N-diethylthiocarbamate, S-benzylN,N-di-sec.-butylthiocarbamate and S-propylN-ethyl-N-butylthiocarbamate.

The thiolcarbamates of the formula IV and their herbicidal activity arealready known (see U.S. Pat. Nos. 2,913,327, 3,037,853, 3,185,720,3,198,786 and 3,582,314).

In the formula V, R⁴ preferably represents an optionally substitutedradical selected from pyrazol-1-yl, imidazol-1-yl, 1,2,4-triazol-1-yl,1,2,3-triazol-1-yl, 1,3,4-triazol-1-yl, 1,2,3,4-tetrazol-1-yl andpyrrol-1-yl. Preferred substituents are: halogen (especially fluorine,chlorine and bromine) and alkyl with 1 to 4 carbon atoms. X and Y areidentical or different and preferably represent straight-chain orbranched alkyl with 1 to 4 carbon atoms. Z preferably representschlorine or bromine and the index n represents 0, 1 or 2.

Specific examples of acetanilides of the formula V which may bementioned are:2-methyl-6-ethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide,2,6-diethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide,2,6-diethyl-N-(1,2,4-triazol-1-yl-methyl)-chloroacetanilide,2,6-dimethyl-N-(1,2,4-triazol-1-yl-methyl)-chloroacetanilide,2-methyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide,2,5-dimethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide,2,3-dimethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide,2-methyl-6-ethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilidehydrochloride, 2,6-diethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilidehydrochloride,2,6-diethyl-N-[(3,5-dimethyl-pyrazol-1-yl)-methyl]-chloroacetanilide,2,6-diethyl-N-[(3-chloro-1,2,4-triazolyl)-methyl]-chloroacetanilide,2-methyl-6-ethyl-N-[(3,5-dimethyl-pyrazol-1-yl)-methyl]-chloroacetanilide,2-tert.-butyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide,2-methyl-6-ethyl-N-[(3-bromo-5-methyl-pyrazol-1-yl)-methyl]-chloroacetanilide,2-methyl-6-ethyl-N-[(3-chloro-1,2,4-triazolyl)-methyl]-chloroacetanilideand 2,6-diethyl-N-[(4-chloro-pyrazol-1-yl)-methyl]-chloroacetanilide.

Further preferred acetanilides of the formula V are listed in thefollowing Table 1.

                  TABLE 1                                                         ______________________________________                                         ##STR11##                                                                    Example                                                                       No.    X        Y.sub.n   Z   R.sup.4                                         ______________________________________                                        V-1    C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  Pyrazol-1-yl                                    V-2    C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  1,2,4-Triazol-1-yl                              V-3    i-C.sub.3 H.sub.7                                                                      6-i-C.sub.3 H.sub.7                                                                     Cl  Pyrazol-1-yl                                    V-4    CH.sub.3 6-C.sub.2 H.sub.5                                                                       Cl  1,2,4-Triazol-1-yl                              V-5    CH.sub.3 6-C.sub.2 H.sub.5                                                                       Cl  Pyrazol-1-yl                                    V-6    C.sub.2 H.sub.5                                                                        4,6-(CH.sub.3).sub.2                                                                    Cl  Pyrazol-1-yl                                    V-7    CH.sub.3 4,6-(CH.sub.3).sub.2                                                                    Cl  Pyrazol-1-yl                                    V-8    C.sub.2 H.sub.5                                                                        4-CH.sub.3,                                                                             Cl  Pyrazol-1-yl                                                    6-C.sub.2 H.sub.5                                             V-9    i-C.sub.3 H.sub.7                                                                      6-i-C.sub.3 H.sub.7                                                                     Cl  1,3,4-Triazol-1-yl                              V-10   i-C.sub.3 H.sub.7                                                                      6-i-C.sub.3 H.sub.7                                                                     Cl  1,2,4-Triazol-1-yl                              V-11   C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  Pyrrol-1-yl                                     V-12   i-C.sub.3 H.sub.7                                                                       --       Cl  1,2,4-Triazol-1-yl                              V-13   CH.sub.3 6-C.sub.2 H.sub.5                                                                       Cl  1,2,3,4-Tetrazol-1-yl                           V-14   i-C.sub.3 H.sub.7                                                                       --       Cl  Pyrazol-1-yl                                    V-15   C.sub.2 H.sub.5                                                                         --       Cl  1,2,4-Triazol-1-yl                              V-16   CH.sub.3 6-CH.sub.3                                                                              Cl  Pyrazol-1-yl                                    V-17   CH.sub.3 6-CH.sub.3                                                                              Cl  1,2,4-Triazol-1-yl                              V-18   CH.sub.3 5-CH.sub.3                                                                              Cl  1,2,4-Triazol-1-yl                              V-19   CH.sub.3  --       Cl  Pyrazol-1-yl                                    V-20   CH.sub.3  --       Cl  1,2,4-Triazol-1-yl                              V-21   CH.sub.3 5-CH.sub.3                                                                              Cl  Pyrazol-1-yl                                    V-22   CH.sub.3 3-CH.sub.3                                                                              Cl  1,2,4-Triazol-1-yl                              V-23   CH.sub.3 3-CH.sub.3                                                                              Cl  Pyrazol-1-yl                                    V-24   C.sub.2 H.sub.5                                                                        6-CH.sub.3                                                                              Cl  Pyrazol-1-yl (xHCl)                             V-25   C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  Pyrazol-1-yl (xHCl)                             V-26   C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  3,5-Dimethyl-pyrazol-1-yl                       V-27   C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  Bromomethyl-pyrazolyl                           V-28   C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  3-Chloro-1,2,4-triazol-1-yl                     V-29   CH.sub.3 6-C.sub.2 H.sub.5                                                                       Cl  3,5-Dimethyl-pyrazol-1-yl                       V-30   C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  3-Methyl-pyrazol-1-yl                           V-31   C.sub.2 H.sub.5                                                                        6-CH.sub.3                                                                              Cl  3-Methyl-pyrazol-1-yl                           V-32   C(CH.sub.3).sub.3                                                                       --       Cl  Pyrazol-1-yl                                    V-33   C(CH.sub.3).sub.3                                                                       --       Cl  1,2,4-Triazol-1-yl                              V-34   C.sub.2 H.sub.5                                                                        6-CH.sub.3                                                                              Cl  Bromo-methyl-pyrazolyl                          V-35   CH.sub.3 6-C.sub.2 H.sub.5                                                                       Cl  4-Chloro-pyrazol-1-yl                           V-36   CH.sub.3 6-C.sub.2 H.sub.5                                                                       Cl  3-Chloro-1,2,4-triazol-1-yl                     V-37   C.sub.2 H.sub.5                                                                        6-CH.sub.3                                                                              Cl  2,4,5-Trichloro-imidazol-                                                     1-yl                                            V-38   C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  4-Chloro-pyrazol-1-yl                           V-39   C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  1,2,3,4-Tetrazol-1-yl                           V-40   C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Br  Pyrazol-1-yl                                    V-41   CH.sub.3 6-C.sub.2 H.sub.5                                                                       Br  Pyrazol-1-yl                                    V-42   C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Cl  Imidazol-1-yl                                   V-43   C.sub.2 H.sub.5                                                                        6-C.sub.2 H.sub.5                                                                       Br  1,2,4-Triazol-1-yl                              V-44   CH.sub.3 6-C.sub.2 H.sub.5                                                                       Br  1,2,4-Triazol-1-yl                              ______________________________________                                    

The acetanilides of the formula V and their herbicidal activity, andherbicidally active acid addition salts and metal salt complexes thereofare already known (see DE-OS (German Published Specification) No.2,648,008 and DE-OS (German Published Specification) No. 2,704,281).

In the formula VI, A preferably represents oxygen, sulphur or thegrouping --NR¹⁰, wherein R¹⁰ represents hydrogen, straight-chain orbranched alkyl with 1 to 4 carbon atoms or aryl with 6 to 10 carbonatoms (especially phenyl), it being possible for the aryl radical tocarry one or more substituents selected from halogen, alkyl with 1 to 4carbon atoms, alkoxy with 1 or 2 carbon atoms, alkylthio with 1 or 2carbon atoms, cyano, nitro and haloalkyl with up to 2 carbon atoms andup to 5 identical or different halogen atoms (preferred halogens beingfluorine or chlorine ). R⁷ preferably represents hydrogen or methyl. R⁸in the formula VI preferably represents hydrogen, straight-chain orbranched alkyl with 1 to 4 carbon atoms, haloalkyl with up to 3 carbonatoms and up to 5 identical or different halogen atoms (preferredhalogens being fluorine or chlorine, and trifluoromethyl being mentionedas an example), alkenyl or alkynyl with in either case 2 to 4 carbonatoms, cycloalkyl with 5 to 7 carbon atoms or halogen (especiallyfluorine, chlorine or bromine). R⁸ furthermore preferably representsaryl with 6 to 10 carbon atoms (especially phenyl), it being possiblefor the aryl radical to carry one or more substituents selected fromhalogen, alkyl with 1 to 4 carbon atoms, alkoxy with 1 or 2 carbonatoms, alkylthio with 1 or 2 carbon atoms, cyano, nitro and haloalkylwith up to 2 carbon atoms and up to 5 identical or different halogenatoms (preferred halogens being fluorine or chlorine and trifluoromethylbeing mentioned as a specific example of haloalkyl). R⁸ furthermorepreferably represents aralkyl with 6 to 10 carbon atoms in the aryl partand 1 to 4 carbon atoms in the alkyl part (especially benzyl), it beingpossible for the aralkyl radical to carry, on the aryl part, one or moresubstituents selected from halogen, alkyl with 1 to 4 carbon atoms,alkoxy with 1 to 2 carbon atoms, alkylthio with 1 to 2 carbon atoms,cyano, nitro and haloalkyl with up to 2 carbon atoms and up to 5identical or different halogen atoms (preferred halogens being fluorineor chlorine, and trifluoromethyl being mentioned as a specific exampleof haloalkyl). R⁸ also preferably represents the grouping --OR¹¹, --SR¹¹or --NR¹⁰ R¹¹, wherein R¹⁰ has the preferred meanings which have alreadybeen mentioned above for this radical, and R¹¹ represents hydrogen,straight-chain or branched alkyl with 1 to 4 carbon atoms, haloalkylwith 1 to 3 carbon atoms and up to 5 identical or different halogenatoms (preferably halogens being fluorine and chlorine, andtrifluoromethyl being mentioned as an example), alkenyl or alkynyl within either case 2 to 4 carbon atoms, cycloalkyl with 5 to 7 carbon atomsor aralkyl with 6 to 10 carbon atoms in the aryl part and 1 to 4 carbonatoms in the alkyl part (especially benzyl), it being possible for thearalkyl radical to carry, on the aryl part, one or more substituentsselected from halogen, alkyl with 1 to 4 carbon atoms, alkoxy with 1 or2 carbon atoms, alkylthio with 1 or 2 carbon atoms, cyano, nitro andhaloalkyl with up to 2 carbon atoms and up to 5 identical or differenthalogen atoms (preferred halogens being fluorine or chlorine, andtrifluoromethyl being mentioned as a specific example of haloalkyl). Inthe formula III, R⁵ preferably represents straight-chain or branchedalkyl with 1 to 4 carbon atoms, R⁶ preferably represents straight-chainor branched alkyl with 1 to 4 carbon atoms, fluorine, chlorine orbromine, and R⁹ preferably represents chlorine, bromine or iodine. Theindex p represents 0, 1 or 2.

Specific examples of acetanilides of the formula VI which may bementioned are:2,6-diethyl-N-[(2-methyl-1,3,4-oxadiazol-5-yl)-methyl]-chloroacetanilide,2,6-dimethyl-N-[(2-methyl-1,3,4-oxadiazol-5-yl)-methyl]-chloroacetanilide,2-ethyl-6-methyl-N-[(2-methyl-1,3,4-oxadiazol-5-yl)-methyl]-chloroacetanilideand2-tert.-butyl-N-[(2-methyl-1,3,4-oxadiazol-5-yl)-methyl]-chloroacetanilide

Further preferred acetanilides of the formula VI are listed in thefollowing Table 2.

                                      TABLE 2                                     __________________________________________________________________________     ##STR12##                         (VI)                                       Example                                                                       No.  R.sup.7                                                                         R.sup.8     R.sup.6                                                                            R.sub.p.sup.5                                                                      A      R.sup.9                                   __________________________________________________________________________    VI-1 H CH.sub.3    CH.sub.3                                                                           6-C.sub.2 H.sub.5                                                                  O      Cl                                        VI-2 H SCH.sub.3   C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                  NCH.sub.3                                                                            Cl                                        VI-3 H CH.sub.3    C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                  O      Cl                                        VI-4 H CH.sub.3    CH.sub.3                                                                           6-CH.sub.3                                                                         O      Cl                                        VI-5 H CH.sub.3    C(CH.sub.3).sub.3                                                                   --  O      Cl                                        VI-6 H SCH.sub.2CHCH.sub.2                                                                       C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                   ##STR13##                                                                           Cl                                        VI-7 H                                                                                ##STR14##  CH.sub.3                                                                           6-C.sub.3 H.sub.5                                                                   ##STR15##                                                                           Cl                                        VI-8 H C.sub.2 H.sub.5                                                                           CH.sub.3                                                                           6-C.sub.2 H.sub.5                                                                  O      Cl                                        VI-9 H C.sub.2 H.sub.5                                                                           C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                  O      Cl                                        VI-10                                                                              H i-C.sub.3 H.sub.7                                                                         CH.sub.3                                                                           6-C.sub.2 H.sub.5                                                                  O      Cl                                        VI-11                                                                              H CH.sub.3    CH.sub.3                                                                           3-CH.sub.3                                                                          ##STR16##                                                                           Cl                                        VI-12                                                                              H CH.sub.3    C.sub.2 H.sub.5                                                                    6-C.sub.2 H.sub.5                                                                  O      Br                                        VI-13                                                                              H CH.sub.3    CH.sub.3                                                                           6-C.sub.2 H.sub.5                                                                  O      Br                                        VI-14                                                                              H CH.sub.3    i-C.sub.3 H.sub.7                                                                  6-i-C.sub.3 H.sub.7                                                                O      Cl                                        __________________________________________________________________________

The acetanilides of the formula (VI) and their herbicidal activity arealready known (compare DE-OS (German Published Specification) No.2,805,757).

Further preferred acetanilides with which the compounds of the formula(I) according to the invention can be employed as antidotes are thecompounds of the formulae (VII) and (VIII). These substances and theirherbicidal activity are already known (see U.S. Pat. No. 3,442,945 andDE-OS (German Published Specification) No. 2,328,340).

The N-acyl-piperidones of the formula (I) according to the invention areparticularly suitable for protecting important crop plants, such asmaize, soya bean, cotton, sugar beet, cereals, rice and cane sugar, fromherbicidal damage by thiolcarbamates and acetanilides.

The active compound combinations according to the invention, whichcomprise an N-acyl-piperidone of the formula (I) and at least oneherbicidally active thiolcarbamate and/or at least one herbicidallyactive acetanilide, exhibit a very good action against broadleaved weedsand graminaceous weeds in numerous crops of useful plants. They cantherefore be used for selectively combating weeds in numerous crops ofuseful plants. By weeds, in the broadest sense, there are to beunderstood in this context all plants which grow in locations where theyare undesired.

The active compound combinations according to the present invention maybe used, for example, to combat the following plants:

dicotyledon weeds of the genera Sinapis, Lepidium, Galium, Stellaria,Matricaria, Anthemis, Galinsoga, Chenopodium, Urtica, Senecio,Amaranthus, Portulaca, Xanthium, Convolvulus, Ipomoea, Polygonum,Sesbania, Ambrosia, Cirsium, Carduus, Sonchus, Rorippa, Rotala,Lindernia, Lamium, Veronica, Abutilon, Emex, Datura, Viola, Galeopsis,Papaver, Centaurea and Solanum; and

monocotyledon weeds of the genera Echinochloa, Setaria, Panicum,Digitaria, Phleum, Poa, Festuca, Eleusine, Brachiaria, Lolium, Bromus,Avena, Cyperus, Sorghum, Agropyron, Cynodon, Monochoria, Fimbristylis,Sagittaria, Eleocharis, Scirpus, Paspalum, Ischaemum, Sphenoclea,Dactyloctenium, Agrostis, Alopecurus and Apera.

The active compound combinations according to the present invention maybe used, for example, as selective herbicides in the following cultures:

dicotyledon cultures of the genera Gossypium, Glycine, Beta, Daucus,Phaseolus, Pisum, Solanum, Linum, Ipomoea, Vicia, Nicotiana,Lycopersicon, Arachis, Brassica, Lactuca, Cucumis, and Cucurbita; and

monocotyledon cultures of the genera Oryza, Zea, Triticum, Hordeum,Avena, Secale, Sorghum, Panicum, Saccharum, Ananas, Asparagus andAllium.

The active compound combinations according to the invention areparticularly suitable for selectively combating weeds in maize, soyabean, cotton, sugar beet, cereals, rice and cane sugar. The antidotesaccording to the invention can be converted, if appropriate as a mixturewith the herbicidal active compounds with which they are employed, intothe customary formulations, such as solutions, emulsions, wettablepowders, suspensions, powders, dusting agents, foams, pastes, solublepowders, granules, suspension-emulsion concentrates, natural andsynthetic materials impregnated with active compound, very fine capsulesin polymeric substances and in coating compositions, for use on seed.

These formulations are produced in known manner, for example by mixingthe antidotes according to the invention, if appropriate as a mixturewith the herbicidal active compounds with which they are employed, withextenders, that is to say liquid or solid or solid diluents or carriers,optionally with the use of surface-active agents, that is to sayemulsifying agents and/or dispersing agents and/or foam-forming agents.In the case of the use of water as an extender, organic solvents can,for example, also be used as auxiliary solvents.

As liquid diluents or carriers, especially solvents, there are suitablein the main, aromatic hydrocarbons, such as xylene, toluene or alkylnaphthalenes, chlorinated aromatic or chlorinated aliphatichydrocarbons, such as chlorobenzenes, chloroethylenes or methylenechloride, aliphatic or alicyclic hydrocarbons, such as cyclohexane orparaffins, for example mineral oil fractions, alcohols, such as butanolor glycol as well as their ethers and esters, ketones, such as acetone,methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, orstrongly polar solvents, such as dimethylformamide anddimethyl-sulphoxide, as well as water.

As solid carriers there may be used ground natural minerals, such askaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite ordiatomaceous earth, and ground synthetic minerals, such ashighly-dispersed silicic acid, alumina and silicates. As solid carriersfor granules there may be used crushed and fractionated natural rockssuch as calcite, marble, pumice, sepiolite and dolomite, as well assynthetic granules of inorganic and organic meals, and granules oforganic material such as sawdust, coconut shells, maize cobs and tobaccostalks.

As emulsifying and/or foam-forming agents there may be used non-ionicand anionic emulfifiers, such as polyoxyethylene-fatty acid esters,polyoxyethylene-fatty alcohol ethers, for example alkylaryl polyglycolethers, alkyl sulphonates, alkyl sulphates, aryl sulphonates as well asalbumin hydrolysis products. Dispersing agents include, for example,lignin sulphite waste liquors and methylcellulose.

Adhesive such as carboxymethylcellulose and natural and syntheticpolymers in the form of powders, granules or latices, such as gumarabic, polyvinyl alcohol and polyvinyl acetate, can be used in theformulations.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian Blue, and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs or metal phthalocyaninedyestuffs, and trace nutrients, such as salts of iron, manganese, boron,copper, cobalt, molybdenum and zinc.

The formulations in general contain between 0.1 and 95% by weight ofantidote or antidote and herbicidal active compound, preferably between0.5 and 90%.

The antidotes according to the invention, as such or in the form oftheir formulations, can, as stated above, also be employed as mixtureswith herbicidal active compounds, finished formulations or tank mixingbeing possible. Mixtures with other active compounds, such asfungicides, insecticides, acaricides, nematicides, bird repellants,growth factors, plant nutrients and agents which improve soil structureare also possible.

The antidotes according to the invention or mixtures of the antidotesaccording to the invention and a herbicidal active compound can beemployed as such, in the form of their formulations or in the use formsprepared therefrom by further dilution, such as ready-to-use solutions,suspensions, emulsions, powders and granules. They may be used in thecustomary manner, for example by watering, spraying, atomizing, dustingor scattering, dry dressing, moist dressing, wet dressing, slurrydressing or encrusting.

The antidotes according to the invention can be applied by methodscustomary for antidotes of this type. Thus, the antidotes according tothe invention can be applied either before or after the herbicide, orcan be applied together with the herbicide. If the herbicide is usedbefore or after sowing, crop plants can also be protected from damage bytreating the seed with the antidotes before sowing (dressing). A furtherpossible way of using the antidotes is to apply them to the seed furrowduring sowing. If the plants are seedlings, these can be treated withthe antidotes before being transplanted.

When the antidotes according to the invention are employed, thecustomary amounts, at the location, of the particular herbicides areapplied. The amounts of herbicidal active compound used vary between 0.5and 5 kg/ha. The amount of antidote used is independent of the herbicideand of the amount of herbicidal active compound used. In general, theamounts of antidotes according to the invention applied are between 0.1and 5 kg/ha in the case of treatment of the soil surface, preferablybetween 0.2 and 4 kg/ha. In the case of seen treatment, the amounts ofantidotes according to the invention applied are in general between 10and 300 g per kilogram of seed, preferably between 25 and 200 g perkilogram of seed.

The weight ratios of antidotes to herbicidal active compounds in theactive compound combinations according to the invention can vary withinrelatively wide limits. In general, 0.04 to 1.0 part by weight,preferably 0.1 to 0.5 part by weight, of antidote of the formula (I) ispresent per 1 part by weight of herbicidal active compound.

Thus, the present invention also provides an antidote compositioncontaining as active ingredient a compound of the formula (I) inadmixture with a solid diluent or carrier or in admixture with a liquiddiluent or carrier containing a surface-active agent.

The present invention also provides a method of protecting crop plantsfrom damage by herbicidally active thiolcarbamates or herbicidallyactive acetanilides in which there is applied to the plants, or to ahabitat thereof, a compound of the formula (I) alone or in the form of acomposition containing as active ingredient a compound of the formula(I) in admixture with a diluent or carrier.

The present invention also provides crops protected from damage byherbicidally active thiolcarbamates or by herbicidally activeacetanilides by being grown in areas in which immediately prior toand/or during the time of the growing a compound of the formula (I) wasapplied, alone or in admixture with a diluent or carrier.

The present invention also provides a herbicidal composition thatcontains as active ingredients (1) a compound of the formula (I) and (2)at least one herbicidally active compound selected from thiolcarbamatesand acetanilides, alone or in admixture with a solid or liquid diluentor carrier.

The present invention also provides a method of combating weeds, inwhich there is applied to the weeds, or to a habitat thereof, aherbicidal composition according to the present invention.

The present invention further provides crops protected from damage byweeds by being grown in areas in which immediately prior to and/orduring the time of the growing, a herbicidal composition of the presentinvention was applied.

It will be seen that the usual methods of providing a harvested crop maybe improved by the present invention.

PREPARATIVE EXAMPLES EXAMPLE 1 ##STR17##

First of all 30.4 g (0.2 mol) of 1.8-diaza-bicyclo [5.4.0] undec-7-enein 50 ml of acetonitrile followed by 14.7 g (0.1 mol) of dichloroacetylchloride were added dropwise to a solution of 15.4 g (0.1 mol) ofpiperidone-(4)-hydrochloride hydrate in 150 ml of acetonitrile at 20° C.The reaction mixture was subsequently stirred at 20°-25° C. for 5 hours.Thereafter, the reaction mixture was poured into 400 ml of water. Theaqueous solution was extracted twice with 100 ml of toluene in eachcase. The combined toluene extracts were dried over sodium sulphate andthen concentrated. 14 g (66.6% of theory) ofN-dichloroacetyl-piperidone-(4) were obtained in this manner in the formof yellow crystals of melting point 85°-87° C.

EXAMPLE 2 ##STR18##

N-(α-chloropropionyl)-piperidone-(4) was obtained in the form of yellowcrystals of melting point 52° C. by reactingpiperidone-(4)-hydrochloride hydrate with α-chloro-propionic acidchloride according to the method described in Example 1. Yield: 50% oftheory.

The good activity of the antidotes according to the invention can beseen from the example which follows.

In this example, the compounds indicated below are employed ascomparison compounds: ##STR19##(N-Dichloroacetyl-cis/trans-decahydroquinoline) ##STR20##(N-Dichloroacetyl-2-ethyl-piperidine)

Furthermore, the acetanilide indicated below is employed as theherbicidal active compound in this example: ##STR21##(2-Methyl-6-ethyl-N-(pyrazol-1-yl-methyl)-chloroacetanilide).

EXAMPLE A Pre-emergence test

Solvent: 5 parts by weight of acetone

Emulsifier: 1 part of weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 1 part by weightof herbicidal active compound or antidote, or of a mixture of antidoteand herbicidal compound, was mixed with the stated amount of solvent,the stated amount of emulsifier was added and the concentrate wasdiluted with water to the desired concentration.

Seeds of the test plants were sown in normal soil and, after 24 hours,watered with the herbicide preparation or antidote preparation or withthe preparation of antidote and herbicidal active compound. It wasexpedient to keep constant the amount of water per unit area. Theconcentration of the active compound in the preparation was of noimportance, only the amount of active compound applied per unit areabeing decisive. After three weeks, the degree of damage to the plantswas rated in % damage in comparison to the development of the untreatedcontrol. The figures denoted:

0%=no action (like untreated control)

100%=total destruction

Evaluation of the test results showed that the compound (1) (seepreparative Example 1) was more suitable for protecting crop plants fromdamage by the compound (C) than the comparison compounds (A) and (B).

It will be understood that the specification and examples areillustrative, but no limitative of the present invention and that otherembodiments within the spirit and scope of the invention will suggestthemselves to those skilled in the art.

What is claimed is:
 1. An N-Acyl-piperidone of the formula ##STR22## wherein R is methyl or chloro.
 2. Compound as claimed in claim 1, wherein R is methyl.
 3. Compound as claimed in claim 1, wherein R is chloro. 